The invention relates to a cover rail corner connection between two matched parts of connecting rod fittings which are to be fixed essentially at a right angle to one another at the wing of at the frame of a window or of a door. Cover rails having two longitudinal edges are braceable against groove steps of a connecting rod slot in the profile of the wing or the frame. These rails are fixable by means of screws directly transverse to their planes and penetrating into the groove bottom. They are connectable with the aid of connecting links which can be brought into mutually, positively locking engagement.
A cover rail corner connection which has no loose component parts and needs no tools for its mounting but which is so designed that on mounting, the connecting parts are automatically brought into engagement, is basically shown in German Patent No. 23 02 538. The connecting parts in this case are formed as U-shaped hooks meshing in a claw-like manner, firmly arranged at the cover rail ends. The lateral flanks of a rectangular hook mouth of the one hook run vertically and the side flanks of the rectangular hook mouth of the other hook run parallel, to the specific cover rail plane. In the connecting position in each case the free end of the one hook engages into the hook mouth of the other hook. The arrangement of the hooks is such that, on mounted cover rails, the hooks are taken up by the connecting rod groove, so that the hooks have a smaller width than the cover rails and are arranged symmetrically to the longitudinal axis of the cover rails.
In further development of this construction, German reference No. OS 23 65 893 shows a cover rail corner connection which is distinguished by the fact that each hook is shaped as a double hook. On one of the cover rails the double hook has a somewhat C-shaped cross-sectional configuration in its longitudinal direction, where the ends of the side flanks are facing towards one another. On the other cover rail, the double hook has a corresponding outer contour of somewhat T-shape (the limited outer contour transverse to its plane,) where the ends of the side flanks are directed away from each other. The somewhat C-shaped part is located at a shaped part which is firmly connected with theinner surface of the cover rail and is closed by means of a limit tang which forms a supporting plate for the T-shaped double hook of the second cover rail.
This prior cover rail corner construction has proved itself advantageous in practical application because it provides an additional improvement of the positive lock between the two cover rails. It also allows a production-favorable construction of the cover rail ends which are to be coupled with one another.
Likewise the German Patent No. 23 02 538 and German reference No. OS 23 27 086 teach a cover rail corner connection which offers the possibility to interconnect the two cover rails in the corner area in such a manner that even before mounting them at the wing or frame of a window these two parts can no longer become detached. This advantage is achieved by the fact that a saw-toothed projection is provided as side flank, limiting the hook mouth at a spacing from the inside of the cover rail and running parallel to the cover rail plane. This defines a pocket which is essentially directed away from the inside of the cover rail in transverse direction. On the side flank of this pocket a stop is provided corresponding in spacing to the thickness of the second cover rail. This stop forms a support for the rear side of the second cover rail in order that this can engage (with limited horizontal swing relative to the first cover rail) with the opening of an eyelet which pushes into the hook mouth in a positively locking manner with the approximately saw-toothed projection.
The particular advantage on the cover rail corner connection according to FIGS. 1 and 2 of the German reference No. OS 23 27 086 resides in the fact that the engaging of the hook ends of the cover rails can be accomplished in all cases in a simple and reliable manner. The ends of the two cover rails which are to be intercoupled are plugged together at an obtuse angle and then the engagement is secured by bringing them into an angular position of about 90.degree. by swiveling them relative to one another.
The invention has the object to develop an improvement in the cover rail corner connection of the German references Nos. OS 23 65 893 and OS 23 27 086. By means of the shaped part arranged in the interior angle of the cover rail corner connection - and thus taken up by the connecting rod groove - the previously interconnected cover rails (connected with one another prior to being mounted) can no longer get out of engagement during execution of the mounting operation. They form, together with the other fitting parts, an angular pre-assembled structural unit. The unit is three- dimensionally secured by the double hooks which intermesh in a claw-like manner.